ABC Chess

By Jeff "Cavebear" Stroud

Introduction

ABC chess is played on a normal 8x8 chessboard. Each side has
an army composed of a King, 8 Pawns, and 7 other pieces.

Setup

Imagine three different pieces whose moves do not overlap. Call these
pieces A, B, and C. Now let there be three pieces whose moves are a
combination of a pair of A, B, and C above. Call these pieces AB, AC,
and BC. Now let there be a piece whose moves are a combination of all
three pieces A, B, and C. Call this piece ABC.

Set up white pieces from a1 to h1 as follows:

a1

b1

c1

d1

e1

f1

g1

h1

ABC

BC

AC

C

K

A

B

AB

Set up the white pawns on a2 through h2. Set up the
black pieces to mirror white's pieces.

Rules

ABC Chess game is played by rules of International Chess, except for the pieces
and some slight modifications to the special rules.

Special Rules:

Castling -- Castling is allowed between the King and the corner
pieces, as in regular chess, except that the pieces in the corners are
the AB and the ABC.

Pawn Promotion -- The first pawn promotion must be to an A, B or C.
The second pawn promotion must be to an AB, AC, or BC. The third pawn
promotion and any after that must be to an ABC.

The Pieces

Obviously, in theory, any set of ABC pieces ought to be approximately
equal in value to any other set having a similar net value of A+B+C.
An ABC army will have a total mobility value equal to 4x(A+B+C). This
means that an ABC army will be approximately equal to the mobility of
the regular chess army when A+B+C = 31/4 = 7.75.

Some Examples:

(Note that in the following list many pieces are defined using Ralph
Betza's funny
notation.)

[1] The VLeaper jumps two
squares orthogonally, then may step one square diagonally outward
if the square first landed in is empty.
[2] The Ski-Bishop moves like
a regular Bishop, except that it leaps over the first square travelled
over. See George Jelliss' page
A Guide to Variant Chess for
further details.

Different Armies for White and Black

This game was conceived as an alternate armies variant. The players
are free to choose any ABC combinations mutually agreed upon as being
equal in strength. More adventurous players can pit an ABC army
against one of the already existing alternate armies, such as those
extensively tested by Ralph Betza and friends. The example armies
above are in the right ballpark for that, although not finely
balanced. Feedback is welcome.

Equipment

Veteran variant players will have no problem coming up with a suitable
set of pieces. For those who have an Omega Chess set, the following
piece representation can be used: